Compatible and reactive vinyl copolymer resn

ABSTRACT

A terpolymer of vinyl chloride, vinyl acetate and an acrylic ester having the formula:   WHEREIN R&#39;&#39;, R2 and R3 may be hydrogen and methyl, in which the vinyl chloride mer content is about 50 to about 69 weight percent, based on the terpolymer weight, the acrylic ester mer content is about 2 weight percent to about 18 weight percent, based on the terpolymer weight, and the vinyl acetate mer content is at least 25 weight percent, based on the terpolymer weight, and said terpolymer has an inherent viscosity of about 0.15 to about 0.5, determined at 30* C using 0.2 grams of the terpolymer in a deciliter of cyclohexanone. These terpolymer resins can be employed alone or in admixture with other resins (such as nitrocellulose and polyurethanes) to make useful coatings.

United States Patent [191 Montgomery [451 Aug. 28, 1973 COMPATIBLE ANDREACTIVE VINYL COPOLYMER RESN [75] Inventor: Donald R. Montgomery,Charleston,

W. Va.

[22] Filed: Nov. 19, 1971 [21] Appl. No.: 200,569

[52] US. Cl 260/80.75, 260/16, 260/17 R, 260/32.8 R, 260/77.5 AP,260/859 PV, 117/155 UA, 117/157 [51] Int. Cl. C08f 15/40 [58] Field ofSearch 260/80.75

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,097,613 H1968England 260/80.75

Primary Examiner.loseph L. Schofer Assistant Examiner-Stanford M. LevinAttorney-Paul A. Rose et a1.

[57] ABSTRACT A terpolymer of vinyl chloride, vinyl acetate and anacrylic ester having the formula:

wherein R, R and R may be hydrogen and methyl, in which the vinylchloride mer content is about 50 to about 69 weight percent, based onthe terpolymer weight, the acrylic ester mer content is about 2 weightpercent to about 18 weight percent, based on the terpolymer weight, andthe vinyl acetate mer content is at least 25 weight percent, based onthe terpolymer weight, and said terpolymer has an inherent viscosity ofabout 0.15 to about 0.5, determined at 30 C using 0.2 grams of theterpolymer in a deciliter of cyclohexa none. These terpolymer resins canbe employed alone or in admixture with other resins (such asnitrocellulose and polyurethanes) to make useful coatings.

1 Claim, No Drawings COMPATIBLE AND REACTIVE VINYL COPOLYMER RESN Vinylchloride polymers have been used for a long time in the manufacture ofcoatings, generally as paints, varnishes and the like. These polymersare typically interpolymers, that is, made from vinyl chloride and atleast one other ethylenically unsaturated monomer, such as vinylacetate, partially hydrolyzed vinyl acetate (as formed within thepolymer to produce a terpolymer), maleic acid, and the like. With theexception of the copolymer of vinyl chloride and vinyl acetatecontaining 40 weight percent vinyl acetate, which was marketedcommercially for only a few years, none of the vinyl polymer resins arecompatible with nitrocellulose.

This point is significant, since compatibility of the vinyl polymerswith nitrocellulose provides a substantial advantage. Nitrocellulose isthe most widely employed resin in the manufacture of lacquers. It is arelatively hard, brittle resin which can be plasticized and alsomodified by other resins to produce films having desirable properties.It is employed as a resin solution having fast-dry lacquer propertiesdue to its ability to quickly release the solvents employed.

Since the vinyl polymers are employed with solvents, they also dry inthe same manner as nitrocellulose lacquers, that is, by evaporation ofthe solvement to deposit a film of the resin on the surface. Therefore,the utilization of these polymers with nitrocellulose could providesubstantial benefits. For example, the vinyl resins are typically lessexpensive than the nitrocellulose resin and, hence, their inclusion in anitrocellulose resin formulation would lower the cost of such aformulation. However, such a use of vinyl resins with a consequentreduction in properties of the resulting film or coating would notnecessarily be an advantage.

A significant factor in the utilization of vinyl chloride interpolymersin nitrocellulose formulations is the degree of compatibility of theinterpolymers with other film fonning aids which are incorporated in thetypical nitrocellulose coating composition. For example, there areemployed alkyd resins of the oxidizing types, which are film-formers,and of the non-oxidizing types which are not film-formers. Alkyd resinswhen corporated in nitrocellulose coating compositions enhance theadhesion qualities of the film, provide films having better body, andserve as a plasticizer for the nitrocellulose. There is also provided inthe coating composition plasticizers, such as the conventional phthalateester plasticizers, which serve to control film properties such astoughness and flexibility. They are usually the lowest cost modifiersemployed in the nitrocellulose composition. Another class of ingredientsadded to nitrocellulose formulations are hard resins or rosins which areused to increase the body of the film and its gloss and improve handlingproperties, especially sandability.

Nitrocellulose is also employed in cross-linking systems that give filmshaving improved resistance to solvents, chemicals and stains as comparedto the lacquers. A crosslinkable nitrocellulose finish would generallycontain the nitrocellulose resin, and alkyd resin and a co-reactant,such as a urea-formaldehyde or melamine-formaldehyde resin or anisocyanato containing urethane resin. Though plasticizers and hardresins or rosins could be added to such formulations, they are usuallynot employed because they detract from the overall performancecharacteristics of the film.

From the above, it is quite apparent that the object herein is toprovide vinyl chloride interpolymers which can be employed broadly innitrocellulose containing compositions and possess utility in and ofthemselves as useful film-formers. The vinyl chloride interpolymers ofthis invention are not only compatible with nitrocellulose, therefore,are suitably employable therewith in the manufacture of lacquers, theyare also readily compatible with the other additives to the usualnitrocellulose compositions such as the plasticizers, the hard resinsand rosins, and the like and are generally compatible with alkyd resinsin admixture with nitrocellulose. In addition, the vinyl chlorideinterpolymers of this invention can be very satisfactorily employed incrosslinkable nitrocellulose compositions because they can be used toincrease the crosslink density of the film by virtue of the presence inthe vinyl chloride interpolymers of this invention of reactivefunctional groups capable of interpolymerization by interaction withother functional groups in the mixture.

The vinyl chloride interpolymers of this invention are resinousterpolymers of vinyl chloride, vinyl acetate and an acrylic ester of theformula:

31 Q {In wherein R, R and R may be hydrogen and methyl. The proportionsof each terrnonomer is important in providing the various propertiescited herein. The vinyl chloride mer content is present in an amountfrom about 50 to about 69 weight percent, based on the weight of theterpolymer. The acrylic ester mer content may be as low as about 2weight percent and may be as high as about 18 weight percent, based onthe weight of the terpolymer. The remainder of the terpolymer weight isfrom vinyl acetate mers, however, the vinyl acetate content of theterpolymer is preferably in excess of about 25 weight percent of theweight thereof. When the vinyl acetate content is less than about 25weight percent, the terpolymer has less than the desired compatibilitywith other resins, particularly nitrocellulose.

Theterpolymers of this invention can be coreacted with isocyanatecontaining urethane prepolymers to form excellent crosslinked films.Illustrative isocyanate containing urethanes suitable for cross-linkingthe terpolymers of this invention are made by reacting a polyol with astoichiometric excess of a polyisocyanate, that is, the resultingurethane reaction product contains free isocyanato groups. Suchurethanes are usually called polyurethane prepolymers by the trade. Forexample, a polyether diol or polyester diol is reacted with adiisocyanate in a mole ratio of diol to diisocyanate of less than 1. Theresulting polymer possesses unreacted isocyanato groups at the terminalportion of the polymer. Qne can effect the same reaction with a trio]and/or tetrol with a diisocyanate or triisocyanate, etc. Such technologyis well known.

The terpolymers of this invention are made by conventional free-radicalpolymerization techniques. The polymerization may be carried out by theconventional suspension, emulsion or solution techniques. The mostdesirable method for making the terpolymer is by solu tionpolymerization. This is achieved in a solvent for the resultingterpolymer as well as the monomers employed in making it. Suitablesolvents are the conventional ester solvents such as butyl acetate,ethyl acetate, isopropyl acetate, n-propyl acetate, and the like, aswell as the ketone solvents such as methyl ethyl ketone, methyl-n-butylketone, methyl isopropyl ketone, and the like. The process employed formaking the terpolymer of this invention is not critical and suchtechnology is well understood by those in the art. It is preferred,however, to carry out the process in such a manner as to promotecompositional uniformity in the terpolymer structure. Illustrative ofthe procedure for making such terpolymers is the followingpolymerization example:

Vinyl chloride (224 grams), vinyl acetate (320 grams), betahydroxypropylacrylate (16 grams) and isopropyl acetate (1040 grams) were charged to a2- liter stainless steel autoclave and the temperature raised to 69 C.An initial feed stream of 12 grams of a 5 weight percent solution ofisopropyl peroxydicarbonate initiator in isopropyl acetate was providedto the autoclave and thereafter the stream was added at a rate of 12grams per hour. When polymerization started, a mixture of 510 grams ofvinyl chloride, 280 grams of vinyl acetate, and 60 grams ofhydroxypropyl acrylate was fed to the autoclave at a rate equal to therate of conversion of monomers to polymer in order to maintain constantmonomer to monomer ratios and monomers to solvent ratio in theautoclave. When the monomer feed was completed the unreacted monomerswere stripped from the varnish by conventional techniques and thecontained resin solids adjusted to 40 percent by addition of solvent.

The various terpolymers described hereinafter were made by the abovetechnique, and the amounts of each different type of mer within theterpolymer was controlled by the amount employed in effecting thereaction, based on coordinating the feed rate of each reactant with itsrespective rate of polymerization. The technique for the manufacture ofthe terpolymer is not a part of this invention.

As pointed out above, the terpolymers of this invention most desirablypossess a minimum amount of vinyl acetate derived mers in theterpolymer. Such is necessary in order to effect the requisitecompatibility with nitrocellulose and this provides an overall utilityfactor not heretofore obtainable from terpolymers having the same mersin its construction but in different proportions, see British Pat. No.No. 1,097,613.

In the preferred use of the terpolymers of this invention, they areemployed in a solvent solution of an active solvent such as describedabove with respect to polymer manufacture.

Another factor significant in the utilization of the vinyl terpolymersof this invention is molecular weight. Molecular weight of theterpolymer has been found to be a factor which determines itscompatibility with other resins such as nitrocellulose and isocyanatocontaining polyurethanes. Defining molecular weight in terms of theterpolymers viscosity, the terpolymers of this invention desirablycontain an inherent viscosity of about 0.15 to about 0.5 determined bydissolving 0.2 grams of resin in a deciliter of cyclohexanone andmeasured at 30 C. Too low an inherent viscosity results in poor filmproperties and too high an inherent viscosity will adversely affect theability to effectively blend the terpolymer with nitrocellulose resinsin making lacquers.

The terpolymers of this invention can be employed in a variety ofcoating formulations with a variety of resins such as urea-formaldehyde,melamineformaldehyde resins, alkyd resins, nitrocellulose, urethaneresins, and the like. Standard formulating techniques may be employed inthe utilization of these terpolymers.

The following examples describe the manufacture of coating compositionsin which, with stirring, the components recited in each example wereblended to form the coating compositions characterized.

EXAMPLE 1 Use of the terpolymer with nitrocellulose as paper coatings.

by wt., dry basis RSNC A see. 100 33 Vinyl terpolymer 50 67 resinMinimum heat seal 450F. 275F. 450F. 400F. temperature at 20 psi, 0.4sec. Gloss 33 45 38 42 Blocking test at 3psi, F. 1 hr. Pass Pass PassPass 5psi, F. 24 hrs. Pass Fail Pass Slight where: Pass means coatingdid not adhere to another coating sample, under the test conditions.Fail means coating adhered to another coating sample, under the testconditions.

l. A terpolymer of 59 weight percent vinyl chloride, 8.9 weight percentbeta-hydroxypropylacrylate, 32.1 weight percent vinyl acetate having aninherent viscosity of 0.34.

2. Where nitrocellulose (RSNC 1/2 sec.) was employed alone, it wasdissolved in a 90 weight acetone/10 weight 5: ethanol mixture. Wherevinyl terpolymer resin was employed alone, it was dissolved in a 50weight% acetone/50 weight isopropyl acetate mixture. Where thenitrocellulose and the vinyl terpolymer resin were blended, the solventswere 70 weight acetone, 5 weight ethanol and 25 weight percent isopropylacetate. All of the solvent solutions were 20 weight solids.

EXAMPLE 2 Use of the terpolymers with nitrocellulose to make a furniturelacquer:

FORMULATIONS A B(Control) by weight, dry basis RSNC 1/2 sec 35 50 Vinylterpolymer resin 15 Coconut alkyd resin 40 40 Dioctyl phthalate 10 10Solids content at 20.2% 18.2% 22 secs. 4 Ford Cup Swanl Hardness 107 108Print Test: 1/2 psi, 4 hrs, 140F. No Print No Print l/2 psi, 4 hrs.,120F. No Print No Print l/2 psi, 18 hrs, 75F. No Print No Print 17 HourResistance to: Alcohol, 50% No Effect No Efi'ect Acetic acid, 5% NoEffect No Effect Merthiolate No Efiect No Effect NaOH, 10% Slight etchof severe etch of Surface Surface l. A terpolymer of 59 weight percentvinyl chloride, 8.9 weight percent gamma-hydroxypropylacrylate, 32.1weight percent vinyl acetate having an inherent viscosity of 0.34.

Solvents employed,

I: by weight 3. Solvents employed 2: by Wt. Methyl ethyl ketone 15 20Use of the terpolymer with nitrocellulose in a reactive type furniturecoating:

1. A terpolymer of 59 weight percent vinyl chloride, 8.9 weight percentbetahydroxypropylacrylate, 32.1 weight percent vinyl acetate having aninherent viscosity of 0.34. 2. See footnote 2, example 2. 3. Seefootnote 3, example 2.

The polyurethanes described in the following examples were made inaccordance with the following procedure:

To a liter flask equipped with a stirrer, thermometer, reflux condenser,dry nitrogen purge and means of heating and cooling is charged theisocyanate (e.g. tolylene diisocyanate) and solvent. The polyol is addedto the isocyanate at such a rate that the temperature does not exceed 55C. After the polyol addition is complete, the temperature is increasedto 80 C. and held for approximately five hours.

In the following examples the polyols were Niax Polyol PCP 0240 andPCP-0210, trademarks of Union Carbide Corporation, New York, N.Y. Bothare formed by reacting caprolactone with a glycol. PCP- 0240 has amolecular weight of 2,000 and PCP-0210 has a molecular weight of 850.

EXAMPLE 4 Prepolymers, as defined below, were made by the aboveprocedure employing the following material. The properties of therespective prepolymers are tabulated below.

Formulation prepolyrner prepolymer prepolymielil' NlAX Polyol 1.0 equiv.1.0 equiv. PCP-0240 NlAX Polyol 1.0 equiv. PCP-0210 Tolylenediisocyanate' 2.0 equiv. 2.0 equiv.

6 bis(4-isocyanatophenyl)- methane 2.0 equiv. Toluene 25% 25% 25%Typical properties Color, Gardner 1.0 1.0 l .0 Free NCO, 96 2.51 5.242.32 Viscosity, cps. at 25C. 1000 5000 1000 1. Usual isomeric mixture of2,4- and 2,6-to1ylene diioscyanate.

FORMULATION A B C D Vinyl terpolymer resin parts by weight 25 25 25 25Prepolymer 1, parts by weight 26.5 l5 Prepolymer ll, parts by weight26.5 Prepolymer 111, parts by weight 26.5 Amine, parts by weight 1.5 1.51.5 Solvent (3), weight 65 65 65 65 Cure at C 1 hour 1 hour 1 hour 2hours pot life at Room Temperature about about about about 24 hours 24hours 24 hours 30 hours physical properties Tentile strength, psi 50008000 4160 4000 Elongation, 475 295 460 260 modulus, 100%, psi 300 220modulus, 300%, psi 640 2500 480 1200 hardness, shore A 82 84 90 abrasionresistance,

Mg" 1.1 5.7 adhesion (5) excellexcellexcellexcellent ent ent ent l) 40%Solution in isopropylacetate of terpolymer of Example 1. (2)4,4'-Methylene-bis (Z-chloroaniline) (MOCA) (3) 50/50 weight blend ofToluene/methyl ethyl ketone (4) Taber Abrasion, CS-l7 Wheel 1000 gms,3000 revolutions (5) Tape Adhesion to poly(ethylene terephthalate) filmWhat is claimed is: l. A terpolymer of vinyl chloride, vinyl acetate andan acrylic ester having the formula:

wherein R, R and R may be hydrogen and methyl, in which the vinylchloride mer content is about 50 to about 69 weight percent, based onthe terpolymer weight, the acrylic ester mer content is about 2 weightpercent to about 18 weight percent, based on the terpolymer weight, andthe vinyl acetate mer content is at least 25 weight percent, based onthe terpolymer weight, and said terpolymer has an inherent viscosity ofabout 0.15 to about 0.5, determined at 30 C. using 0.2 grams of theterpolymer in a deciliter of cyclohexanone.

* t t t UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,755,271 Dated August 28, 1973 Inventor(s) Donald R. Montgomery It iscertified that error appeare in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below: It the title;"RESN" should read --RESIN--. Column 1, in the title; "RESN" should read"RESIN". Column 3, line 48; delete secgnd appearing "No. Column 5, line2; "A should read Signed and sealed this 21st day of January 1975.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents DRM PO-IOSO (10-69) USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINTINGOFFICE ISQ 0-368-33L

